Fluorinated oils and greases are employed as lubricants in demanding applications. A well-known class of fluorinated lubricants are the perfluoroalkylpolyether oils available as commercial products under the tradenames KRYTOX® (E. I. du Pont de Nemours and Company, Wilmington Del.), FOMBLIN® (Ausimont, Milan, Italy), and DEMNUM® (Daiken Industries, Japan). It is found in practice that in oxygen containing environments, the perfluoroalkylpolyethers may undergo degradation at temperatures as low as 150° C., with concomitant corrosion of some metal surfaces such as aluminum, iron and alloys thereof. There is a need for lubricating oils with improved stability at elevated temperature that results in less corrosion of a lubricated metal surface.
Anolick et al., in U.S. Pat. Nos. 5,478,905, 5,663,255, 5,637,663, and 6,133,389, describes a continuous co-telomerization process comprising contacting a large excess of hexafluoropropylene with fluoro-olefins such as tetrafluoroethylene (TFE)and vinylidene fluoride (VF2) and a radical initiator under a pressure of about 41 to about 690 MPa, and a temperature above about 200° to about 400° C. to produce amorphous cotelomers. Also described was the equipment for conducting the cotelomerization with a residence time of about 10 s to about 30 min.
Tuminello et al., U.S. Pat. No. 6,767,626, discloses use of high HFP content co-telomers for protection of stone surfaces